Office of
Biological and Environmental Research Weekly Report
September 8,
2008
Urbanization Effects in
Large-Scale Temperature Records, With an Emphasis on China P. D. Jones, D. H. Lister,
and Q. Li. Global surface
temperature trends, based on land and marine data, show warming of about 0.8oC
over the last 100 years. This rate of warming is sometimes questioned
because of the existence of well-known Urban Heat Islands (UHIs). In a recent paper in Journal of Geophysical
Research, BER-sponsored
researcher Phil Jones of the University
of East Anglia UK and his group show
examples of the UHIs
at London and Vienna, where city center sites are warmer
than surrounding rural locations. Both of these UHIs
however do not contribute to warming trends over the 20th century because the
influences of the cities on surface temperatures have not changed over this
time. A new homogenized station data set with gridded temperature products is
compared for China
and an attempt is made to assess possible urban influences using sea surface
temperature (SST) data sets for the area east of the Chinese mainland. It is
demonstrated that all the land-based data sets for China agree exceptionally well and
that their residual warming compared to the SST series since 1951 is relatively
small compared to the large-scale warming. Urban-related warming over China is shown
to be about 0.1oC decade -1 over the period 1951–2004, with true climatic
warming accounting for 0.81oC over this period.
Reference:
Jones, P. D., D. H. Lister, and Q. Li (2008), Urbanization effects in
large-scale temperature records, with an emphasis on China, JOURNAL OF GEOPHYSICAL
RESEARCH, VOL. 113, D16122, doi:10.1029/2008JD009916,
2008
Media Interest: Maybe
Contact: Anjuli Bamzai, SC-23.1, (301)
903-0294
ARM Climate Research
Facility (ACRF) Data Helps Diagnose Validity of Climate Models. DOE’s ACRF data are
part of the Community Atmospheric Model’s (CAM)
standard diagnostic software package. The diagnostic package is an
important tool for model developers to evaluate the impact of new physical
parameterizations, e.g., clouds, radiation, etc., on model simulations of
climate. The CAM is the atmospheric component
of the Community Climate System Model (CCSM), one of two national climate
models. Using the diagnostic package, modelers can quickly evaluate changes
made to components of a model by comparing those changes with the corresponding
best estimate of observations. DOE’s ACRF long-term
data set includes information on clouds, radiation and associated atmospheric
data collected at several sites around the world, with very different
geographies, and over a time frame sufficient for statistical evaluation of
climate models.
Media Interest: No
Contact: Wanda Ferrell,
SC-23.1, (301) 903- 0043